a) Field of the Invention
The invention is directed to a pull-turn bolt latch for mounting in an opening in a thin wall, particularly for securing plug-ins, doors or flaps in switch cabinets, comprising a housing that can be secured in a non-round opening in a thin wall, a shaft which is provided with an external thread and which is mounted in the housing so as to be rotatable but fixed with respect to axial displacement, on which external thread a bolt provided with a matching threaded bore hole is guided in the housing so as to be acted upon by pressure by a spring engaging around the shaft such that when the shaft is rotated by hand or by a tool in the stop position at the outer end of the shaft or when the pressure is relaxed the bolt carries out a rotational movement of at least 90° with the shaft, and in the position remote of the stop position accompanied by axial guidance in an axial slot formed for the bolt in the housing or other guidance during the rotational movement of the shaft carries out a translational movement in axial direction, wherein the housing has a head part such as a flange which covers the outer edge of the opening and a body part proceeding from this head part and penetrating the opening.
b) Description of the Related Art
A pull-turn bolt latch of the type mentioned above is already known from pages 62, 63 and 67 of the catalog “Southco Compression Latches” by the firm of Southco. In the known latch, fastening to the sheet metal is carried out by means of a coupling nut from the front according to page 62 of the catalog, and by means of a nut from the rear according to page 63 of the catalog, and by means of two rivets or two screws according to page 67 of the catalog.
One of the drawbacks of the prior art is that mounting is very complicated. Also, the nuts or screws can loosen as a result of vibration and can fall into the circuit and substantially impair the reliability and operating safety of the circuits contained therein. Further, the tongue can be moved into the open position and into the closed position over the entire axial path of the tongue in the housing, i.e., user error is also possible.
In the prior art, handles must also be fastened by screws for pulling out the drawer or plug-in or for opening the door or flap, which increases the risk of loosened screws.